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/*
This file is part of TALER
(C) 2014, 2015, 2016 INRIA
TALER is free software; you can redistribute it and/or modify it under the
terms of the GNU Affero General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.
TALER is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
TALER; see the file COPYING. If not, If not, see <http://www.gnu.org/licenses/>
*/
/**
* @file backend/taler-merchant-httpd_contract.c
* @brief HTTP serving layer mainly intended to communicate with the frontend
* @author Marcello Stanisci
*/
#include "platform.h"
#include <jansson.h>
#include <taler/taler_signatures.h>
#include <taler/taler_json_lib.h>
#include "taler-merchant-httpd.h"
#include "taler-merchant-httpd_parsing.h"
#include "taler-merchant-httpd_auditors.h"
#include "taler-merchant-httpd_exchanges.h"
#include "taler-merchant-httpd_responses.h"
/**
* Check that the given JSON array of products is well-formed.
*
* @param products JSON array to check
* @return #GNUNET_OK if all is fine
*/
static int
check_products (json_t *products)
{
size_t index;
json_t *value;
int res;
if (! json_is_array (products))
{
GNUNET_break (0);
return GNUNET_SYSERR;
}
json_array_foreach (products, index, value) {
const char *description;
const char *error_name;
unsigned int error_line;
struct GNUNET_JSON_Specification spec[] = {
GNUNET_JSON_spec_string ("description", &description),
/* FIXME: there are other fields in the product specification
that are currently not labeled as optional. Maybe check
those as well, or make them truly optional. */
GNUNET_JSON_spec_end()
};
/* extract fields we need to sign separately */
res = GNUNET_JSON_parse (value,
spec,
&error_name,
&error_line);
if (GNUNET_OK != res)
{
GNUNET_break (0);
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Product description parsing failed at #%u: %s:%u\n",
(unsigned int) index,
error_name,
error_line);
return GNUNET_SYSERR;
}
GNUNET_JSON_parse_free (spec);
}
return GNUNET_OK;
}
/**
* Manage a contract request. In practical terms, it adds the fields
* 'exchanges', 'merchant_pub', and 'H_wire' to the contract 'proposition'
* gotten from the frontend. Finally, it adds (outside of the
* contract) a signature of the (hashed stringification) of the
* contract (and the hashed stringification of this contract as well
* to aid diagnostics) to the final bundle, which is then send back to
* the frontend.
*
* @param rh context of the handler
* @param connection the MHD connection to handle
* @param[in,out] connection_cls the connection's closure (can be updated)
* @param upload_data upload data
* @param[in,out] upload_data_size number of bytes (left) in @a upload_data
* @return MHD result code
*/
int
MH_handler_contract (struct TMH_RequestHandler *rh,
struct MHD_Connection *connection,
void **connection_cls,
const char *upload_data,
size_t *upload_data_size)
{
json_t *root;
json_t *jcontract;
int res;
struct TMH_JsonParseContext *ctx;
struct TALER_ContractPS contract;
struct GNUNET_CRYPTO_EddsaSignature contract_sig;
struct TALER_Amount total;
struct TALER_Amount max_fee;
uint64_t transaction_id;
json_t *products;
struct GNUNET_TIME_Absolute timestamp;
struct GNUNET_TIME_Absolute refund_deadline;
struct GNUNET_TIME_Absolute expiry;
struct GNUNET_JSON_Specification spec[] = {
TALER_JSON_spec_amount ("amount", &total),
TALER_JSON_spec_amount ("max_fee", &max_fee),
GNUNET_JSON_spec_uint64 ("transaction_id", &transaction_id),
/* The following entries we don't actually need, except to check that
the contract is well-formed */
GNUNET_JSON_spec_json ("products", &products),
GNUNET_JSON_spec_absolute_time ("timestamp", ×tamp),
GNUNET_JSON_spec_absolute_time ("refund_deadline", &refund_deadline),
GNUNET_JSON_spec_absolute_time ("expiry", &expiry),
GNUNET_JSON_spec_end()
};
if (NULL == *connection_cls)
{
ctx = GNUNET_new (struct TMH_JsonParseContext);
ctx->hc.cc = &TMH_json_parse_cleanup;
*connection_cls = ctx;
}
else
{
ctx = *connection_cls;
}
res = TMH_PARSE_post_json (connection,
&ctx->json_parse_context,
upload_data,
upload_data_size,
&root);
if (GNUNET_SYSERR == res)
return MHD_NO;
/* the POST's body has to be further fetched */
if ((GNUNET_NO == res) || (NULL == root))
return MHD_YES;
jcontract = json_object_get (root, "contract");
if (NULL == jcontract)
{
json_decref (root);
return TMH_RESPONSE_reply_external_error (connection,
"contract request malformed");
}
/* extract fields we need to sign separately */
res = TMH_PARSE_json_data (connection,
jcontract,
spec);
if (GNUNET_NO == res)
{
json_decref (root);
return MHD_YES;
}
if (GNUNET_SYSERR == res)
{
json_decref (root);
return TMH_RESPONSE_reply_external_error (connection,
"contract request malformed");
}
/* check contract is well-formed */
if (GNUNET_OK != check_products (products))
{
GNUNET_JSON_parse_free (spec);
json_decref (root);
return TMH_RESPONSE_reply_external_error (connection,
"products in contract request malformed");
}
/* add fields to the contract that the backend should provide */
json_object_set (jcontract,
"exchanges",
trusted_exchanges);
json_object_set (jcontract,
"auditors",
j_auditors);
json_object_set_new (jcontract,
"H_wire",
GNUNET_JSON_from_data_auto (&h_wire));
json_object_set_new (jcontract,
"merchant_pub",
GNUNET_JSON_from_data_auto (&pubkey));
/* create contract signature */
contract.purpose.purpose = htonl (TALER_SIGNATURE_MERCHANT_CONTRACT);
contract.purpose.size = htonl (sizeof (contract));
contract.transaction_id = GNUNET_htonll (transaction_id);
TALER_amount_hton (&contract.total_amount,
&total);
TALER_amount_hton (&contract.max_fee,
&max_fee);
GNUNET_assert (GNUNET_OK ==
TALER_JSON_hash (jcontract,
&contract.h_contract));
GNUNET_CRYPTO_eddsa_sign (&privkey.eddsa_priv,
&contract.purpose,
&contract_sig);
/* return final response */
res = TMH_RESPONSE_reply_json_pack (connection,
MHD_HTTP_OK,
"{s:O, s:O, s:O}",
"contract", jcontract,
"merchant_sig", GNUNET_JSON_from_data_auto (&contract_sig),
"H_contract", GNUNET_JSON_from_data_auto (&contract.h_contract));
GNUNET_JSON_parse_free (spec);
json_decref (root);
return res;
}
/* end of taler-merchant-httpd_contract.c */
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